Apparatus for distilling hydrocarbon oils



ct 11, 1932. F. A. HOWARD ET AL 1,332,606

APPARATUS FOR DISTILLING HYDROCARBON OILS Original Filed April 10. 1922 7 Sheets-Sheet l c? dMm/YNVENTORJ. m M 5m "ATTORNEY Oct. 11, 1932. F. A. HOWARD ET AL APPARATUS FOR DISTILLING HYDROCARBON OILS bri inal Filed April 10. 1922 7 Sheets-Sheet 3 M0415W I-NVENTORS,

ATTORNEY.

INVENTORS.

' ATTORNEY Get. 11, 1932. F. A. HOWARD ET AL APPARATUS FORDIS TILLING HYDROCARBON OILS Original Filed April 10- 1922 7 Sheets-Sheet 4 Oct. 11, 1932. F. A. HOWARD ET AL APPARATUS FOR DISTILLI-NG HYDROCARBON OILS VIII/Ill ATTORNEY Oct. 11, 1932- F. A. HOWARD ET AL 1,882,606

APPARATUS FOR DISTILLING HYDROCARBON OILS Original Filed April 10. 1922 7 Sheets-Sheet 6 Condenser L E 94 z .Boz/er w TOR 5,5 M K ZWQV VEN .5 I

BY .m ATTORNEY:

Oct. '11, 1932. F. A. HOWARD ET AL 1,882,606

- APPARATUS FOR DISTILLING HYDROCARBON OILS Original Filed April 10. 1922 7 Sheets-Sheet .7

fi-zmary/Xeal i'xc/lanyens' l 5 6 i? my I 36? 2] 319a INVEN Tom 40am LM Patented on. 11, 1932 I NITED STATES PATENT OFFICE FRANK A. HOWARD, OF ELIZABETH, NEW'J'EBSEY, WARREN K. LEWIS, OF NEWTON, MASSACHUSETTS, AND HENRY M. NOEL, F ELIZABETH, NEW JERSEY, ASSIGNOBS TO STANDARD OIL DEVELOPMENT COMPANY, A CORPORATION OF DELAWARE APPARATUS FOR DISTILLING HYDBOOABBON OILS original application filed April 10, 1922, Serial No. 551,800. Divided and this application filed October 23,

1928. Serial No. 314,496. a r

The present invention relates to the art of distilling .hydrocarbon oils and more particularly to the distillation of lubricating oils under conditions such as to avoid decomposition or cracking of the material undergoing distillation, with consequent reduction in viscosity and injury of lubricatin qualities. The invention will be fully un erstood from the following description, illustrated by the accompanying drawings, in which:

' Fi ure 1 is a side elevation of a battery of stills suitable for carrying out the invention, showing also the boiler for supplying the heating medium for theTbattei-y of stills;

w) stills, viewed from a plane between the heater and the battery ofstills on the line 2 of Fig. 3; i

Fig. Sis a plan view of the assembly shown go; in Fig. T;

Fig. 4 is a. sectional view through the heater on the line 4 of Fig. 3;

Fig. 5 is a horizontal sectional view through the still within the heater on the as line 5 of Fig. 4:;

Fig. 6 is a longitudinal sectional view through the still in the heater on the line 6 6 of Fig. 5;

Fig. 7 is a broken vertical section through 30) one of the stills of the battery, with its superimposed dephlegmators and fractional condenser;

Fig. 8 is a broken vertical section through a dephlegmating tower and fractional condenser;

Fig. 9 is a transverse sectional view on the line 9 of Fig. 8, and illustrates the construction of several elements of the device, as will be hereinafter pointed out;

40 Fig. 10 is a transverse sectional view on the line 10 of Fig. 7; w

i Fig. 11 is a transverse sectional .view on the-line 11 of Fig.7

a Fig. 12 is a transverse sectional view on theline 12 of Fig. 7; a

Fig. 13 is a vertical sectional view through the condenser box on the line 13 of Fig. 3;

Fig. 14: is a=diagrammatic chart showing the course of travel of the heating medium supplied to the stills; and

Fig. 2 is an end elevation of the battery of Fig. 15 is a diagrammatic chart showing the course of travel of the oil supplied to the stills and the products issuing therefrom.

In accordance with the present invention, the stock to be distilled or reduced, after being preheated, if desired, is continuousl heated by means of a condensing vapor, pre erably one having a temperature of condensation of from 500 F. to 1000 F. at a pressure not to exceed 200 lbs. such as mercury vapor. The oil is subjected in small volumes and for short periods of time to the heat of such vapors, preferably under conditions such that its vaporization is in creased above that which would take place at the same temperature under ordinary atmospheric' conditions, for example, by the application of subatmospheric pressure or of inert gases such as steam or both. In the apparatus illustrated, the oil is passed in continuous flow through a succession or battery of devices in each of which it is subjected to similar treatment at.successively" higher temperatures. 75

Referring more particularly to the draw-' ings, the numerals 20, 21 and 22 indicate three stills forming the battery, each of these being surmounted by an oil separator 24, 24a, 24 and a primary heat exchanger 25, 25a, 25?), which likewise acts as a fractional condenser or dephlegmator (rectifier). The stills are suitably set at successively lower levels in the direction of flow of the oil, as indicated most clearly in Fig. 2. The construction of the stills and the superimposed, g ephlzegmators is most clearly shown in The still is formed as a hollow cylindrical tube in which are two spaced transverse plates 26 and 27. The tubes 28 extend upwardly through the still, 0 ening through the plates 26 and 27 at the ottom and top respectively. The lower plate 26 forms a chamber in the base of the still, into which the oil is introduced through pipe 29. The means provided for injecting inert gas or steam may suitably be the ring 30 mounted in the chamber in the base of the still below the plate 26 and provided with nozzles 31 extending up- 100 wardly into the lower ends of the tubes 28.

Steam or other inert gas may be supplied to this ring through the pipe 32. The heating medium, which may suitably be mercury vapor, is introduced into the space between the plates 26 and 27 surrounding the tubes 28 through pipe 33 and is condensed. The mercury condensed in this space is withdrawn through a pipe 35 opening just above the plate 26.

The oil separator 24 is preferably of greater diameter than the still and may suitably be seated upon a flange 36 formedon the latterbelow its top, thereby forming an annular collecting chamber 37 around the top of the still. The oil flowing upward through the tubes 28 overflows into this chamber37 and is withdrawn from it through pipe 38. Just above the opening of the tubes 28 of still 20, a deflector 41, preferably conical in shape, is supported within the separator 24, its edges being spaced from the wall of the latter. This deflector prevents direct upward flow of the vapors formed in the still and aids in the separation of oil entrained in the vapors.

Upon the separator 24 is mounted a plate 42, provided with a nipple 43. Upon plate .42 is mounted the primary heat exchanger 25,

into which the nipple 43 opens. In the base of the heat exchanger a conical deflector 44 is mounted above the nipple 43. Above the deflector the bafiles 45 aresecured to the wall of the exchanger and compel a circuitous flow of the vapors. Above the baflles are mounted the two spaced plates 46 and 47, be-

tween which extend the vapor tubes 48. Into the space surrounding these the stock to be preheated may be introduced through pipe 49 and it may be withdrawn from the space through pipe 50. A pipe 52 is provided for the withdrawal of condensate from the annular space in the base of the exchanger 25 surrounding the nipple 43.

From the top of the exchanger 25 the uncondensed vapors pass out through vapor pipe 53 to the base of a secondary exchanger 54, of which one is provided for each still.

This exchanger, as shownin Fig. 8, is provided at its lower end with the baflies 55 and above these are mounted the spaced plates 56 and 57, between which extend the vapor tubes 58. A cooling medium, which may suitably be the stock to be preheated, is supplied into the space between the plates 56 and 57 through the pipe 59 and makes its exit through the pipe 60. Condensate formed in the secondary exchanger 54 may .be withdrawn through the pipe 61 near its bottom. The vapors pass out of the secondary exchanger through vapor pipe 62 into the manifold 63, from which they are carried into the base of the final water-cooled condenser 64 of any suitable type, for example, a multiwhirl condenser. From the condenser 64 i the uncondensed gases pass out through pipe 65 to a vacuum pump, or to a gasometer, (not shown) or to the air.

In connection with the battery of stills shown in Figs. 1, 2 and 3, and inthe diagrammatic Figure 15, the several separators and exchangers and other elements which are of identical construction in each still of the battery are distinguished by using the numerals employed above without sutfix in connection with still 20, with the suffix a in connection with still 21, and with the suffix b in connection with still 22.

The stills are heated by means of a condensing vapor which will have a temperature of condensation of 500 to 1000 F. at a pressure not exceeding 200 lbs. per square inch. It is desirable that the pressure at which the vapor has the desired temperature be not too low, say below 2 lbs. absolute, since the difliculties of operation are increased by the use of higher vacuum. The heating medium should preferably not decompose at the temperature employed, nor corrode the apparatus. The high rate of heat transference due to the use of the condensing vapor as a heating medium enables a low temperature difference to be maintained between the temperature of the heating medium and that of the heated oil. The temperature difference is preferably maintained at from 10 to 50 F., although it may reach as high as 200 F. The heating vapor may be superheated when introduced into the heating chamber of the still, if desired.

In the present embodiment of the invention the heating medium selected for the stills is preferably mercury vapor, although vapors of hydrocarbon oil or other vapors having the desired characteristics may be employed, for example, diphenyl, diphenyl oxid, or naphthalene. A mercury boiler 67 is mounted in a suitable setting 66. The construction of this boiler is shown most clearly in Figs. 4, 5 and 6. To the spaced plates 68 and 69 the dished plates 70 and 71 are secured, a chamber being thus formed adjacent each plate. Between the plates 70 and 71 extend the tubes 72, which may suitably be. covered with corrugated cast iron rings 73 to increase the inflow of heat. These tubes open into the aforesaid chambers. concentrically within the tubes 72 are mounted the tubes 74, which extend between the .plates 68 and 69 and form heating means of the nature of fire tubes, through which the combustion gases may pass. The still 67 is'so mounted in the setting 66 that the'combustion gases pass first around the exterior of the tubes 72 and then pass through the tubes 74 to the stack.

The mercury vapors evolved in the boiler 67 pass out through the pipe 75 to a manifold 76, from which they are distributed into the stills through the pipes 33, 33a and 33b. The maximum pressure in the mercury r of the mercurv boiler.

boiler is determined by the setting of safety valve 84:. The pressure within the mercury boiler is controlled by the valve settings on these pipes.

Outlets 34, 34a and 346 are provided for the oil vapor from an upper part of the heating chamber of the stills, thesc outlets being provided with valves 79, 79a and 796 respectively. In beginning operations these valves are opened in order to vent the air contained in the heating chamber and to enable it to be filled with the heating vapors. The valves 7 9, 79 and 79 may then be closed, and mercury condensed in the stills will be discharged through pipes 35, 35 and 35 and will be returned by manifold to theloase The pressure prevailing in the heating chamber of the several stills may be controlled by the valves 79,

79 and 79 in outlet lines 34, 34 and 34"..

The outlet lines 34, 34 and 34' open into line 77, which leads to an intermediate point of the condenser coil 78, the upper end 80 of which may suitably be open to the air to serve as a vent. The condensing area above the point of admission of the pipe 77 is suficient to condense any mercury vapor that may be carried upward. If vacuum operation of the heating system is desired, the open condenser end may suitably be connected to a vacuum pump. From the condenser 0011 the condensed mercury is carried by 'pipe 81 to the base of the mercury boiler, which it enters through the pipe 82. The condenser 7 8 is elevated above the boiler so that the height of mercury in the pipe 81 wlll supply pressure suficient to overcome the pressure maintained in the boiler. The mercury vapor pipe 7 5 may suitably be connected to the condenser coil by a conduit 83 provided with a safety valve84.

The travel of the mercury is shown diagrammatically in Fig. 14, the lines of travel in that figure being given numbers'cone' sponding to the various elements shown in the constructional figures of the drawings.

The oil to be distilled or reduced may be preheated, this being suitably accompllshed as illustrated in the drawings in two stages, an initial preheating being effected in the secondary exchangers and a further preheating-being efiected in the primary exchangers 25, 25a and-25b surmounted 'on the stills 20, 21 and 22. lln Fig. 15 the travel of the oil and the products of distillation and reduction is diagrammatically shown and in this figure various conduits and elements are given the same designating numerals as in the remaining figures of the drawings.

596 respectively. It surrounds the vapor pipes 58 in these exchangers, is heated there in by the vapors fromthe primary heat exchangers 25, 251; and 25b and passes out through pipes 60, 60a and 606 into the maniiold 88. A valved connection 89 is provided between the cold line and the hot manifold 88. The hot oil passes from manifold 88 through pipe 49 into the primary exchanger 25, and is there further heated by the vapors in the tubes 48. The oil then leaves the. exchanger 25 through the pipe 50, a valved bypass 90 being provided between the pipe 50 and the pipe 49. From the pipe 50 the oil passes through valved pipe 91, provided with a valve 91, into the pipe 49a provided with valve 92. The pipe 49a introduces the oil into the exchanger 25a corresponding to the still 21 and it leaves this exchanger through the pipe 50 which is connected by valved bypass 90 with the pipe 91. The oil flows from pipe 56 through valved pipe 91 into the pipe 49", which is provided with valve- 93. The pipe 49 introduces the oil into the exchanger 25) corresponding with still 22, and it leaves this exchanger through pipe 50", which is connected by the valved by-pass 90 with the pipe 91*. The oil, having thus passed successively through the exchangers 25, 25 and 25 is conveyed by valved pipe 94 through the valved pipe 29, which introduces takes place andacquires therein a temperature at which distillation takes place under the conditions prevailing, a suitable temperature being 550 to 600 F. for medium inbricating stocks. The vapors formed in the still 20 rise through the separator 24 and the residual oil or bottoms. together with anvcondensate formed in the dephlegmator 24 discharges through pipe 38 and is conveyed through p pes 97 and 29' into the second still 21. Here the oil is subjected to a similar treatment and the bottoms from the still 21 3 are d scharged through pipe 38, and pass into still 22. Aflike treatment of the oil follows in this still. leaving a reduced bottom having the viscosity desired for the lubricating oil, and the oil thus produced is discharged through pipes 38 and 98. The vaporsfrom still 20, after passing through the dephlegmator rise through the bafiled lower chamber tubes 48, where they act to heat the incoming oil.

Condensates formed in the primary exof the primary exchanger 25 and through the a leo changer 25 are discharged through pipe 52 to ing medium materially improves the heat the cooling coil 99 and the receiving house. transference rate. The vaporization of the- In asimilar way the vapors from the dephlegoil may be further aided by the injection mators 24 and 24" pass through the primary I of steam into the lower ends of the tubes 28 exchangers 25 and 25 and the condensates in the several stills, the steam being supplied from these chambers are likewise discharged from pipe 102 to the pipes, 32, 32 and 32", through pipes 52 and 52 to the cooling coils that in turn supply it to the nipples 31 enter- 99 and 99". The stills 20, 21 and 22 may be ing the lower ends of the still tubes 28. The placed at respectively lower levels so that the relatively shortperiod of application of heat flow of the oil therethrough maybe aided by to the small flowing body of oil is made posgravity. sible by the high ratio of heated surface to The vapors issuing from the primary exvolume and the high heat transfer rate, and changers 25, 25* and 25? pass through the materially reduces the amount of decomposivapor pipes 53, 53 and 53 into the secondary tion, and correspondingly reduces the forexchangers 54, 54 and 54 respectively, mation of less viscous fractions of lower value where they effect initial heating of the stock as lubricants. It will be understood that to be treated and are cooled thereby. It is where reference is made to tubes for carrying readily apparent that water or any other the oil in heat exchange with the mercury suitable cooling medium may be used in any vapor, it is intended that any suitable long or all of the heat exchangers in place of the passageway of narrow cross section may be .oil to be distilled. The condensates from used. The tubes need not be of the cylindrithese exchangers are passed through lines 61, cal form shown.

61" and 61 and cooling coils 101, 101 and Although this invention has been described 101 to the receiving house in which they are in connection with the details of the specific collected. The vapors from the exchangers embodiment of apparatus for carrying it into 54, 54 and 54 pass out through the vapor efiect, it is not intended that these details pipes 62, 62 and 62 and are manifolded, shall be regarded as limitations upon the passing'through the pipe 63 into the condenser scope of the invention except in so far as 64, and the uncondensed vapors pass out to a included in the accompanying claims.

p with a'heating surface of 0.1 to 0.5.square A type of lubricating oil still.

suitable water cooled condenser.

A vacuum This application is a division of our apmay be applied, thereby maintaining the oil plication erial No. 551,300, filed April 10, in the stills 20, 21 and 22 under sub-atmos- 1922. pheric pressure and correspondingly lowering We claim: L the temperature required for its vaporization. 1. In an apparatus for distilling hydro- The heating medium, mercury vapor, for carbon' oil by heat supplied from the vapor example, is supplied to the stills 20,21 and of a distilling medium having a temperature 22 through the valved pipes 33, 33 and 33 of condensation of from 500 to 1,000 F. and, if desired, the pressure in the heating at apressure not exceeding 200 lbs. per square compartments of the stills may be controlled inch and not substantially corrosive nor subindividually by the valves 79, 7 9 and 79 ject to objectionable decomposition at the opon the vapor exit pipes 34, 34 and 34. At erating temperature, the combination of a atmospheric pressure the temperature of the boiler for said medium, a still, means for 'supsaturated mercury vapors is' about 677 F. plying a flowing stream of hydrocarbon oil In the manufacture of solar red oil, for exto said still, tubes in the still for distributing ample, it has been found convenient to mainthe oil therein over a large area, means for tain upon the mercury a pressure of 40 conveying vapors of said distilling medium pounds gauge, at which pressure the satufrom said boiler to said still, meansfor passrated mercury vapors have a temperature of ing said vapors into indirect heat exchange approximately 833 F. The vapors may be relation with the oil in said tubes, means superheated, if desired. As the. oil is flowfor taking oif and separating the heavier oil ing through the heated chamber in continuvapors, means for dephlegmating residual ously flowing streams. of small volume comoil vapors and means for returning distilling pared to the heating surface exposed, it is medium to the boiler. I

rapidly and efficiently heated to the vappriza- 2. Apparatus according to claim 1, in tion temperature. face per cubic foot of oil in accordance with, tubes through which the oil passes and means the present invention exceeds 8 square feet, are provided for supplying the oil substanand is preferably from 20 to 25, as compared tially continuously to said tubes.

3. Apparatus according to claim 1, in

feet per cubic foot of oil heated in the usual which means are provided for independently The rate of regulating the rate of flow of distilling metravel of the oil is such that its total period dium vapor into heat exchange relation with under distillation. is not more than 30 minthe oil in the still.

utes and preferably about 15 minutes. 4..In an apparatus for distilling hydro- The use of the condensing vapor as aheatcarbon oil by heat supplied from the vapor hearea of heated surwhich the still contains a plurality of vertical of condensation of from 500 to 1000 F. at

a pressure not exceeding 200 lbs. persquare inch and not substantially corrosive nor sub ject to objectionable decomposition at the operating temperature, the combination of a boiler for said medium, a still, means for supplying a flowing stream of hydrocarbon oil to said still and for distributing the same therein over a large area, means for convey" ing vapors of said distilling medium from said boiler to said still, means for passing said vapors into indirect heat exchange relation with the oil in said still, means for taking oil and condensing oil vapors, means for returning dIstilling medium to the boiler, a valve controlled pipe in the upper part of said still and adapted to permit regulated withdrawal ofexcess vapors of distilling medium, together with any incondensible gas, means for cooling said vapors and gases to condense the vapors and means for venting said cooled gases from the system.

5. In an apparatus for distilling hydrocarbon oil by heat supplied from the vapor of a distilling medium having a temperature of condensation of from 500 to 1000 F. at a pressure not exceeding 200 lbs. per square inch and not substantially corrosive nor subj ect to objectionable decomposition at the operating temperature, the combination of a boiler for said medium, a still, means for supplying a flowing stream. of hydrocarbon oil to said still, a plurality of tubes in the still for distributin the oil therein over a large area, means or conveying vapors or said distilling medium from said boiler to said still, means for passing said vapors into indirect heat exchange relation with the oil in said tubes, means for taking off and separating heavier oil vapors, means for dephlegmating residual oil vapors, a vent line from the boiler, valve means in said vent line for automatically and independently fixing the maximum pressure on the supply of distilling medium vapors, and a condenser connected to receive any distilling medium vapors discharged through said valve means,

6. Apparatus according to claim 5, in which additional valve means are provided for regulating the pressure of distilling medium vapor in the still. g

7. In combination with a hydrocarbon oil still, means for supplying vapors of a distilling medium for indirect heat exchange with oil insaid still and comprising a boiler pressure control valve substantially corrosive nor subject to objectionable decomposition at the operating temperature, a pipe for conveying vapors of said distilling medium, an oil still receiving said vapors, means for passing oil in narrow streams through said still in indirect heat,

exchange with said vapors, a withdrawal line for any excess of said vapors, a pressure control valve in said withdrawal line, a condenser receiving said excess vapors, means for discharging the material from the condenser to the source of supply of the distillmg medium vapors, and means independent of the pressure control valve for determlning the maximum pressure on the source of distilling medium vapors.

Apparatus according to blaim 9, in i which a control valve is provided in the pipe for conveying vapors of the distilling medium to the still.

FRANK A. HOWARD. WARREN K. LEWIS. c

HENRY M. NOEL. 

